From Mark of the Unicorn:
Motu Pci 424 Drivers Download
Motu Pci-424 Drivers
This install provides compatibility updates for 10.2.7 (and later), as well as Panther 10.3 and G5 compatibility updates. Installer contains drivers for MOTU PCI-324 and PCI-424 audio systems under Mac OSX. This install requires OS 10.2.2 or later. OSX 10.2.4 or higher is highly recommended. MOTU PCI Audio console is provided for PCI-324 and 424 systems. Cuemix and the SMPTE Console is provided for PCI-424 systems. Console applications install into the local directory Applications folder. Cuemix now has control surface support, talkback and listenback capabilities, and I/O port naming under Panther. Refer to .pdf included in installer for update info.
Microsoft
Motu 24I/O drivers updated daily. Windows XP, Vista, 7, 8. O driver downloads using the Motu Driver Update Tool. Motu 24I/O drivers are tiny programs that. Download the latest driver for MOTU PCI Wave Driver, fix the missing driver with MOTU PCI Wave Driver. Download the latest drivers for your MOTU Audio to keep your Computer up-to-date.